Curse of the Last Forge

"It is as if the artisan's wished their works to die as they did. In an inexplicable explosion"- Passage from 'Remnant of Imperial Magic'

In the middle of the night a sonorous explosion shattered the night and could be hear from several hundred leagues away. Dawn came and revealed a crater 150 meters across and about 50 deep, exposing the foundation stones of Tol Vivicor, the Last Imperial Forge.

Manifestation

Any time a magic item that was created by the Imperial Artisan's Guild that comes within one kilometer of the crater that was Tol Vivicar a low hum begins to sound. It is always at the low end of the scale and at first seems to have no clear source.
The longer the magic item remains within the area the louder the sound grows. As it grows to uncomfortable volume it starts to become centered on both the crater of Tol Vivicar as well as the magic item.
If the item remains in the area, anywhere within the 1 kilometer circle, for a quarter of an hour then the item will explode. The strength of the enchantments on the item seems to have a direct corelation to the size of the explosion.
The Wizard Cyril Bendoc conducted several experiments, studying the phenomenon. He described the results in his book Remnants of Imperial Magic. He theorized that the area now contained a negative resonance. This negative resonance caused the magical matrix upon the items the Guild created to frament and that stored energy to escape via an explosion. Lesser items such as stones that would cast a candle's worth of light would explode with enough force to destroy the hand holding it. More intricate and powerful items such as a suit of shadowarmor would cause an explosion big enough to incinerate the one wearing it and anything else within a half dozen paces. The area around the blast crater of the Last forge is littered with small blast marks. None of which has eroded in any way.
This includes the crater of the Forge itself. It still looks as it did when it exploded. Cyril Bendoc remarked on this but had no explanation on how it could be.
Bendoc also noted that no animal could be compelled to enter the area. Carried or drug if one possessed suffient force but no horse nor hound would willingly enter and fought every attempt to force them.

Localization

An amost perfect circle, one kilometer across centered on the crater of Tol Vivicar, is an area that responds destructively if any magic item created by the Imperial Artisan's Guild enters this circle.